The present invention relates to railway locomotive brake control apparatus and particularly to such apparatus as provides a penalty brake application in the event the locomotive engineer to the train is operating in an unsafe condition. For example, conventional 26 type locomotive brake equipment includes a penalty application valve, which operates in a manner fully explained in columns 14 and 15 of the foregoing reference patent, to initiate a brake application in the event the locomotive engineer fails to periodically give an indication of his alertness, or the locomotive traction motors are operating at an excessive speed, or the train speed is exceeding a safe limit. Should one of these conditions arise, a warning whistle is sounded for a predetermined period of time, indicating an impending automatic penalty brake application. In the event the engineer fails to acknowledge the warning whistle by taking corrective action, a penalty brake application will become effective by reason of the penalty application valve's effecting a reduction of equalizing reservoir pressure.
The engineer's automatic brake valve device, employed in the 26 type locomotive brake equipment, is arranged to respond to a reduction of equalizing reservoir pressure, as explained in columns 2, 3, 4, and 5 of the foregoing reference patent, to initiate a corresponding reduction of the train brake pipe pressure, thereby causing the train brakes to apply.
In addition to a relay valve for providing the brake pipe pressure reduction in accordance with the effective equalizing reservoir pressure, there is further provided a manual selector valve and a brake pipe cut-off valve, the latter of which can be conditioned to cut off the flow of brake pipe fluid pressure to and from the engineer's brake valve by manually setting the selector valve in the cut-out position. This permits the engineer's brake valve device to be deactivated or cut out, by isolating it from the brake pipe, for the purpose of conducting brake pipe leakage tests, to permit multiple-unit operation, to haul a dead locomotive, to permit double-heading operation, etc., as set forth in columns 17 and 18 of the foregoing reference patent.
A dangerous and unauthorized operating procedure is being employed surreptitiously by train engineers, wherein the selector valve on the active brake valve is positioned to cause the brake pipe cut-off valve to interrupt the venting of brake pipe pressure when the operator, or train, is operating in an unsafe condition, in order to prevent the brake valve from venting brake pipe pressure in response to a reduction of equalizing reservoir pressure by the penalty application valve. In this way, the engineer is able to nullify the penalty brake application in an unauthorized and improper manner, i.e., without any brake application whatsoever being made.